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Wang Z, Gong W, Yao Z, Jin K, Niu Y, Li B, Zuo Q. Mechanisms of Embryonic Stem Cell Pluripotency Maintenance and Their Application in Livestock and Poultry Breeding. Animals (Basel) 2024; 14:1742. [PMID: 38929361 PMCID: PMC11201147 DOI: 10.3390/ani14121742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2024] [Revised: 05/31/2024] [Accepted: 06/07/2024] [Indexed: 06/28/2024] Open
Abstract
Embryonic stem cells (ESCs) are remarkably undifferentiated cells that originate from the inner cell mass of the blastocyst. They possess the ability to self-renew and differentiate into multiple cell types, making them invaluable in diverse applications such as disease modeling and the creation of transgenic animals. In recent years, as agricultural practices have evolved from traditional to biological breeding, it has become clear that pluripotent stem cells (PSCs), either ESCs or induced pluripotent stem cells (iPSCs), are optimal for continually screening suitable cellular materials. However, the technologies for long-term in vitro culture or establishment of cell lines for PSCs in livestock are still immature, and research progress is uneven, which poses challenges for the application of PSCs in various fields. The establishment of a robust in vitro system for these cells is critically dependent on understanding their pluripotency maintenance mechanisms. It is believed that the combined effects of pluripotent transcription factors, pivotal signaling pathways, and epigenetic regulation contribute to maintaining their pluripotent state, forming a comprehensive regulatory network. This article will delve into the primary mechanisms underlying the maintenance of pluripotency in PSCs and elaborate on the applications of PSCs in the field of livestock.
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Affiliation(s)
- Ziyu Wang
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou 225009, China; (Z.W.); (W.G.); (Z.Y.); (K.J.); (Y.N.); (B.L.)
- Key Laboratory of Animal Breeding Reproduction and Molecular Design for Jiangsu Province, College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China
| | - Wei Gong
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou 225009, China; (Z.W.); (W.G.); (Z.Y.); (K.J.); (Y.N.); (B.L.)
- Key Laboratory of Animal Breeding Reproduction and Molecular Design for Jiangsu Province, College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China
| | - Zeling Yao
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou 225009, China; (Z.W.); (W.G.); (Z.Y.); (K.J.); (Y.N.); (B.L.)
- Key Laboratory of Animal Breeding Reproduction and Molecular Design for Jiangsu Province, College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China
| | - Kai Jin
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou 225009, China; (Z.W.); (W.G.); (Z.Y.); (K.J.); (Y.N.); (B.L.)
- Key Laboratory of Animal Breeding Reproduction and Molecular Design for Jiangsu Province, College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China
| | - Yingjie Niu
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou 225009, China; (Z.W.); (W.G.); (Z.Y.); (K.J.); (Y.N.); (B.L.)
- Key Laboratory of Animal Breeding Reproduction and Molecular Design for Jiangsu Province, College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China
| | - Bichun Li
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou 225009, China; (Z.W.); (W.G.); (Z.Y.); (K.J.); (Y.N.); (B.L.)
- Key Laboratory of Animal Breeding Reproduction and Molecular Design for Jiangsu Province, College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China
| | - Qisheng Zuo
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou 225009, China; (Z.W.); (W.G.); (Z.Y.); (K.J.); (Y.N.); (B.L.)
- Key Laboratory of Animal Breeding Reproduction and Molecular Design for Jiangsu Province, College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China
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X-chromosome reactivation: a concise review. Biochem Soc Trans 2021; 49:2797-2805. [PMID: 34821360 DOI: 10.1042/bst20210777] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 11/03/2021] [Accepted: 11/05/2021] [Indexed: 12/14/2022]
Abstract
Mammalian females (XX) silence transcription on one of the two X chromosomes to compensate the expression dosage with males (XY). This process - named X-chromosome inactivation - entails a variety of epigenetic modifications that act synergistically to maintain silencing and make it heritable through cell divisions. Genes along the inactive X chromosome are, indeed, refractory to reactivation. Nonetheless, X-chromosome reactivation can occur alongside with epigenome reprogramming or by perturbing multiple silencing pathways. Here we review the events associated with X-chromosome reactivation during in vivo and in vitro reprogramming and highlight recent efforts in inducing Xi reactivation by molecular perturbations. This provides us with a first understanding of the mechanisms underlying X-chromosome reactivation, which could be tackled for therapeutic purposes.
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Chen X, Zhu Z, Yu F, Huang J, Jia R, Pan J. Effect of shRNA-mediated Xist knockdown on the quality of porcine parthenogenetic embryos. Dev Dyn 2018; 248:140-148. [PMID: 30055068 DOI: 10.1002/dvdy.24660] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2018] [Revised: 06/27/2018] [Accepted: 07/13/2018] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Parthenogenetically activated oocytes exhibit poor embryo development and lower total numbers of cells per blastocyst accompanied by abnormally increased expression of Xist, a long noncoding RNA that plays an important role in triggering X chromosome inactivation during embryogenesis. RESULTS To investigate whether knockdown of Xist influences parthenogenetic development in pigs. We developed an anti-Xist short hairpin RNA (shRNA) vector, which can significantly inhibit Xist expression for at least seven days when injected at 12-13 hr after parthenogenetic activation. Embryonic cleavage, blastocyst formation, and total blastocyst cell numbers were compared during the blastocyst stage, as well as the expression of an X-linked gene and three pluripotent transcription factors. Knockdown of Xist significantly increases the total blastocyst cell number, but does not influence the rate of embryo cleavage and blastocyst formation. The expressions of Sox2, Nanog, and Oct4 were also significantly improved in the injected embryos compared with the control at the blastocyst stage, but the Foxp3 expression level was not increased significantly. CONCLUSIONS The present study provides valuable information for understanding the role of Xist in parthenogenesis and presents a new approach for improving the quality of porcine parthenogenetic embryos. Developmental Dynamics 248:140-148, 2019. © 2018 Wiley Periodicals, Inc.
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Affiliation(s)
- Xiaoyu Chen
- Institute of Animal Husbandry and Veterinary Science, Zhejiang Academy of Agriculture Science, Hangzhou, Zhejiang, P.R. China
| | - Zhiwei Zhu
- Institute of Animal Husbandry and Veterinary Science, Zhejiang Academy of Agriculture Science, Hangzhou, Zhejiang, P.R. China
| | - Fuxian Yu
- Institute of Animal Husbandry and Veterinary Science, Zhejiang Academy of Agriculture Science, Hangzhou, Zhejiang, P.R. China
| | - Jing Huang
- Institute of Animal Husbandry and Veterinary Science, Zhejiang Academy of Agriculture Science, Hangzhou, Zhejiang, P.R. China
| | - Ruoxin Jia
- Institute of Animal Husbandry and Veterinary Science, Zhejiang Academy of Agriculture Science, Hangzhou, Zhejiang, P.R. China
| | - Jianzhi Pan
- Institute of Animal Husbandry and Veterinary Science, Zhejiang Academy of Agriculture Science, Hangzhou, Zhejiang, P.R. China
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Dianatpour A, Ghafouri-Fard S. Long Non Coding RNA Expression Intersecting Cancer and Spermatogenesis: A Systematic Review. Asian Pac J Cancer Prev 2017; 18:2601-2610. [PMID: 29072050 PMCID: PMC5747377 DOI: 10.22034/apjcp.2017.18.10.2601] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Background: Numerous similarities have been noted between gametogenic and tumorigenic programs in features
such as global hypomethylation, immune evasion, immortalization, meiosis induction, and migration. In addition, aberrant
expression of testis specific genes has been detected in various cancers which has led to categorization of these genes
as “cancer-testis genes”. Most of the examples identified in this category are protein encoding. However, recent studies
have revealed that non-coding RNAs, including long non coding RNAs (lncRNAs), may have essential regulatory
roles in telomere biology, chromatin dynamics, modulation of gene expression and genome structural organization.
All of these functions are implicated in both gametogenic and tumorigenic programs. Methods: In the present study,
we conducted a computerized search of the MEDLINE/PUBMED and Embase databases with the key words lncRNA,
gametogenesis, testis and cancer. Results: We found a number of lncRNAs with essential roles and notable expression
in both gametogenic and cancer tissues. Conclusions: Comparison between cancer tissues and gametogenic tissues
has shown that numerous lncRNAs are expressed in both, playing similar roles in processes modulated by signaling
pathways such as Wnt/β-catenin and PI3K/AKT/mTOR. Evaluation of expression patterns and functions of these
genes should pave the way to discovery of biomarkers for early detection, prognostic assessment and evaluation of
therapeutic responses in cancers.
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Affiliation(s)
- Ali Dianatpour
- Department of Medical Genetics, Faculty of Medicine, Shahid Beheshti University of Medical sciences, Tehran, Iran.
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Mohammed H, Hernando-Herraez I, Savino A, Scialdone A, Macaulay I, Mulas C, Chandra T, Voet T, Dean W, Nichols J, Marioni JC, Reik W. Single-Cell Landscape of Transcriptional Heterogeneity and Cell Fate Decisions during Mouse Early Gastrulation. Cell Rep 2017; 20:1215-1228. [PMID: 28768204 PMCID: PMC5554778 DOI: 10.1016/j.celrep.2017.07.009] [Citation(s) in RCA: 204] [Impact Index Per Article: 29.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 06/07/2017] [Accepted: 07/06/2017] [Indexed: 01/08/2023] Open
Abstract
The mouse inner cell mass (ICM) segregates into the epiblast and primitive endoderm (PrE) lineages coincident with implantation of the embryo. The epiblast subsequently undergoes considerable expansion of cell numbers prior to gastrulation. To investigate underlying regulatory principles, we performed systematic single-cell RNA sequencing (seq) of conceptuses from E3.5 to E6.5. The epiblast shows reactivation and subsequent inactivation of the X chromosome, with Zfp57 expression associated with reactivation and inactivation together with other candidate regulators. At E6.5, the transition from epiblast to primitive streak is linked with decreased expression of polycomb subunits, suggesting a key regulatory role. Notably, our analyses suggest elevated transcriptional noise at E3.5 and within the non-committed epiblast at E6.5, coinciding with exit from pluripotency. By contrast, E6.5 primitive streak cells became highly synchronized and exhibit a shortened G1 cell-cycle phase, consistent with accelerated proliferation. Our study systematically charts transcriptional noise and uncovers molecular processes associated with early lineage decisions.
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Affiliation(s)
- Hisham Mohammed
- Epigenetics Programme, Babraham Institute, Cambridge CB22 3AT, UK
| | | | - Aurora Savino
- Epigenetics Programme, Babraham Institute, Cambridge CB22 3AT, UK
| | - Antonio Scialdone
- EMBL-European Bioinformatics Institute (EMBL-EBI), Wellcome Genome Campus, Cambridge CB10 1SD, UK; Wellcome Trust Sanger Institute, Single-Cell Genomics Centre, Cambridge CB10 1SA, UK
| | - Iain Macaulay
- Wellcome Trust Sanger Institute, Single-Cell Genomics Centre, Cambridge CB10 1SA, UK
| | - Carla Mulas
- Wellcome Trust-Medical Research Council Stem Cell Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QR, UK; Department of Physiology, Development and Neuroscience, University of Cambridge, Tennis Court Road, Cambridge CB2 3EG, UK
| | - Tamir Chandra
- Epigenetics Programme, Babraham Institute, Cambridge CB22 3AT, UK
| | - Thierry Voet
- Wellcome Trust Sanger Institute, Single-Cell Genomics Centre, Cambridge CB10 1SA, UK; Department of Human Genetics, Human Genome Laboratory, KU Leuven, 3000 Leuven, Belgium
| | - Wendy Dean
- Epigenetics Programme, Babraham Institute, Cambridge CB22 3AT, UK
| | - Jennifer Nichols
- Wellcome Trust-Medical Research Council Stem Cell Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QR, UK; Department of Physiology, Development and Neuroscience, University of Cambridge, Tennis Court Road, Cambridge CB2 3EG, UK.
| | - John C Marioni
- EMBL-European Bioinformatics Institute (EMBL-EBI), Wellcome Genome Campus, Cambridge CB10 1SD, UK; Wellcome Trust Sanger Institute, Single-Cell Genomics Centre, Cambridge CB10 1SA, UK; Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge CB2 ORE, UK.
| | - Wolf Reik
- Epigenetics Programme, Babraham Institute, Cambridge CB22 3AT, UK; Wellcome Trust Sanger Institute, Single-Cell Genomics Centre, Cambridge CB10 1SA, UK; Centre for Trophoblast Research, University of Cambridge, Cambridge CB2 3EG, UK.
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Lamas-Toranzo I, Pericuesta E, Bermejo-Álvarez P. Memories of an X-chromosome. Stem Cell Investig 2017; 4:27. [PMID: 28447042 DOI: 10.21037/sci.2017.03.01] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2016] [Accepted: 03/07/2017] [Indexed: 11/06/2022]
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Ordered chromatin changes and human X chromosome reactivation by cell fusion-mediated pluripotent reprogramming. Nat Commun 2016; 7:12354. [PMID: 27507283 PMCID: PMC4987517 DOI: 10.1038/ncomms12354] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Accepted: 06/24/2016] [Indexed: 12/17/2022] Open
Abstract
Erasure of epigenetic memory is required to convert somatic cells towards pluripotency. Reactivation of the inactive X chromosome (Xi) has been used to model epigenetic reprogramming in mouse, but human studies are hampered by Xi epigenetic instability and difficulties in tracking partially reprogrammed iPSCs. Here we use cell fusion to examine the earliest events in the reprogramming-induced Xi reactivation of human female fibroblasts. We show that a rapid and widespread loss of Xi-associated H3K27me3 and XIST occurs in fused cells and precedes the bi-allelic expression of selected Xi-genes by many heterokaryons (30–50%). After cell division, RNA-FISH and RNA-seq analyses confirm that Xi reactivation remains partial and that induction of human pluripotency-specific XACT transcripts is rare (1%). These data effectively separate pre- and post-mitotic events in reprogramming-induced Xi reactivation and reveal a complex hierarchy of epigenetic changes that are required to reactivate the genes on the human Xi chromosome. Reactivation of the inactive X chromosome (Xi) has modelled epigenetic reprogramming in mouse. Here, by using cell fusion between human female fibroblasts and mouse embryonic stem cells, the authors show a complex hierarchy of epigenetic changes that are required to reactivate the genes on the human Xi chromosome.
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Voutsadakis IA. Pluripotency transcription factors in the pathogenesis of colorectal cancer and implications for prognosis. Biomark Med 2016; 9:349-61. [PMID: 25808439 DOI: 10.2217/bmm.15.4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The cancer stem cell hypothesis argues that cancers depend on a specific type of cells, representing usually a small percentage of the total cancer cell population, termed cancer stem cells (or tumor-initiating cells) for their development and propagation. In colorectal cancer these cells express specific surface proteins such as CD133 and CD44 and can recapitulate the whole tumor. Besides expression of these surface markers, stem cells are associated with a network of pluripotency transcription factors, such as Oct4 and Sox2, which is present in them. Pluripotency factors are normally active in early development and characterize primitive cells, able to give rise to all different cell and tissue types of the three embryonic layers. In this review I will discuss the relationship of these factors with pathogenic lesions in colorectal cancer and their prognostic implications.
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Voutsadakis IA. The network of pluripotency, epithelial-mesenchymal transition, and prognosis of breast cancer. BREAST CANCER-TARGETS AND THERAPY 2015; 7:303-19. [PMID: 26379447 PMCID: PMC4567227 DOI: 10.2147/bctt.s71163] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Breast cancer is the leading female cancer in terms of prevalence. Progress in molecular biology has brought forward a better understanding of its pathogenesis that has led to better prognostication and treatment. Subtypes of breast cancer have been identified at the genomic level and guide therapeutic decisions based on their biology and the expected benefit from various interventions. Despite this progress, a significant percentage of patients die from their disease and further improvements are needed. The cancer stem cell theory and the epithelial-mesenchymal transition are two comparatively novel concepts that have been introduced in the area of cancer research and are actively investigated. Both processes have their physiologic roots in normal development and common mediators have begun to surface. This review discusses the associations of these networks as a prognostic framework in breast cancer.
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Affiliation(s)
- Ioannis A Voutsadakis
- Division of Medical Oncology, Department of Internal Medicine, Sault Area Hospital, Sault Ste Marie, ON, Canada ; Division of Clinical Sciences, Northern Ontario School of Medicine, Sudbury, ON, Canada
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Abstract
Reprogramming of somatic cells to induced pluripotent stem cells (iPSCs) requires profound alterations in the epigenetic landscape. During reprogramming, a change in chromatin structure resets the gene expression and stabilises self-renewal. Reprogramming is a highly inefficient process, in part due to multiple epigenetic barriers. Although many epigenetic factors have already been shown to affect self-renewal and pluripotency in embryonic stem cells (ESCs), only a few of them have been examined in the context of dedifferentiation. In order to improve current protocols of iPSCs generation, it is essential to identify epigenetic drivers and blockages of somatic cell reprogramming.
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11
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The chemosensitivity of testicular germ cell tumors. Cell Oncol (Dordr) 2014; 37:79-94. [PMID: 24692098 DOI: 10.1007/s13402-014-0168-6] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/27/2014] [Indexed: 12/13/2022] Open
Abstract
Although rare cancers overall, testicular germ cell tumors (TGCTs) are the most common type of cancer in young males below 40 years of age. Both subtypes of TGCTs, i.e., seminomas and non-seminomas, are highly curable and the majority of even metastatic patients may expect to be cured. These high cure rates are not due to the indolent nature of these cancers, but rather to their sensitivity to chemotherapy (and for seminomas to radiotherapy). The delineation of the cause of chemosensitivity at the molecular level is of paramount importance, because it may provide insights into the minority of TGCTs that are chemo-resistant and, thereby, provide opportunities for specific therapeutic interventions aimed at reverting them to chemosensitivity. In addition, delineation of the molecular basis of TGCT chemo-sensitivity may be informative for the cause of chemo-resistance of other more common types of cancer and, thus, may create new therapeutic leads. p53, a frequently mutated tumor suppressor in cancers in general, is not mutated in TGCTs, a fact that has implications for their chemo-sensitivity. Oct4, an embryonic transcription factor, is uniformly expressed in the seminoma and embryonic carcinoma components of non-seminomas, and its interplay with p53 may be important in the chemotherapy response of these tumors. This interplay, together with other features of TGCTs such as the gain of genetic material from the short arm of chromosome 12 and the association with disorders of testicular development, will be discussed in this paper and integrated in a unifying hypothesis that may explain their chemo-sensitivity.
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Schoorlemmer J, Pérez-Palacios R, Climent M, Guallar D, Muniesa P. Regulation of Mouse Retroelement MuERV-L/MERVL Expression by REX1 and Epigenetic Control of Stem Cell Potency. Front Oncol 2014; 4:14. [PMID: 24567914 PMCID: PMC3915180 DOI: 10.3389/fonc.2014.00014] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Accepted: 01/21/2014] [Indexed: 11/17/2022] Open
Abstract
About half of the mammalian genome is occupied by DNA sequences that originate from transposable elements. Retrotransposons can modulate gene expression in different ways and, particularly retrotransposon-derived long terminal repeats, profoundly shape expression of both surrounding and distant genomic loci. This is especially important in pre-implantation development, during which extensive reprograming of the genome takes place and cells pass through totipotent and pluripotent states. At this stage, the main mechanism responsible for retrotransposon silencing, i.e., DNA methylation, is inoperative. A particular retrotransposon called muERV-L/MERVL is expressed during pre-implantation stages and contributes to the plasticity of mouse embryonic stem cells. This review will focus on the role of MERVL-derived sequences as controlling elements of gene expression specific for pre-implantation development, two-cell stage-specific gene expression, and stem cell pluripotency, the epigenetic mechanisms that control their expression, and the contributions of the pluripotency marker REX1 and the related Yin Yang 1 family of transcription factors to this regulation process.
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Affiliation(s)
- Jon Schoorlemmer
- Regenerative Medicine Program, Instituto Aragonés de Ciencias de la Salud , Zaragoza , Spain ; ARAID Foundation , Zaragoza , Spain
| | - Raquel Pérez-Palacios
- Regenerative Medicine Program, Instituto Aragonés de Ciencias de la Salud , Zaragoza , Spain
| | - María Climent
- Departamento de Anatomía, Embriología y Genética Animal, Facultad de Veterinaria, Universidad de Zaragoza , Zaragoza , Spain
| | - Diana Guallar
- Regenerative Medicine Program, Instituto Aragonés de Ciencias de la Salud , Zaragoza , Spain
| | - Pedro Muniesa
- Departamento de Anatomía, Embriología y Genética Animal, Facultad de Veterinaria, Universidad de Zaragoza , Zaragoza , Spain
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Zhao GQ, Dowell JE. Hematologic malignancies associated with germ cell tumors. Expert Rev Hematol 2014; 5:427-37. [DOI: 10.1586/ehm.12.24] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Jia W, Chen W, Kang J. The functions of microRNAs and long non-coding RNAs in embryonic and induced pluripotent stem cells. GENOMICS PROTEOMICS & BIOINFORMATICS 2013; 11:275-83. [PMID: 24096129 PMCID: PMC4357836 DOI: 10.1016/j.gpb.2013.09.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Revised: 09/02/2013] [Accepted: 09/03/2013] [Indexed: 12/19/2022]
Abstract
Embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) hold immense promise for regenerative medicine due to their abilities to self-renew and to differentiate into all cell types. This unique property is controlled by a complex interplay between transcriptional factors and epigenetic regulators. Recent research indicates that the epigenetic role of non-coding RNAs (ncRNAs) is an integral component of this regulatory network. This report will summarize findings that focus on two classes of regulatory ncRNAs, microRNAs (miRNAs) and long ncRNAs (lncRNAs), in the induction, maintenance and directed differentiation of ESCs and iPSCs. Manipulating these two important types of ncRNAs would be crucial to unlock the therapeutic and research potential of pluripotent stem cells.
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Affiliation(s)
- Wenwen Jia
- Clinical and Translational Research Center of Shanghai First Maternity and Infant Health Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Science and Technology, Tongji University, Shanghai 200092, China
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Dupont C, Gribnau J. Different flavors of X-chromosome inactivation in mammals. Curr Opin Cell Biol 2013; 25:314-21. [PMID: 23578369 DOI: 10.1016/j.ceb.2013.03.001] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Revised: 02/27/2013] [Accepted: 03/13/2013] [Indexed: 12/22/2022]
Abstract
Dosage compensation of X-linked gene products between the sexes in therians has culminated in the inactivation of one of the two X chromosomes in female cells. Over the years, the mouse has been the preferred animal model to study this X-chromosome inactivation (XCI) process in placental mammals (eutherians). Similar to the imprinted inactivation of the paternally inherited X chromosome (Xp) in marsupials (methatherians), the Xp is inactivated during early mouse development. In this eutherian model, cell derivatives of the primitive endoderm (PE) and trophectoderm (TE) will continue to display this imprinted form of XCI. Cells developing from the mouse epiblast will reactivate the Xp, and subsequently initiate XCI of either the Xp or the maternally inherited Xm, in a random manner. Examination of XCI in other eutherians and in metatherians, however, indicates clear differences in the form and timing of XCI. This review highlights and discusses imprinted and random XCI from such a comparative viewpoint.
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Affiliation(s)
- Cathérine Dupont
- Department of Reproduction and Development, Erasmus MC, University Medical Center, 3015GE Rotterdam, The Netherlands
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Isaji Y, Murata M, Takaguchi N, Mukai T, Tajima Y, Imai H, Yamada M. Valproic acid treatment from the 4-cell stage improves Oct4 expression and nuclear distribution of histone H3K27me3 in mouse cloned blastocysts. J Reprod Dev 2013; 59:196-204. [PMID: 23337102 PMCID: PMC3934201 DOI: 10.1262/jrd.2012-156] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
We examined effects of treatment with valproic acid (0, 0.2, 1 or 2 mM, VPA), an
inhibitor of class I and IIa histone deacetylases (HDACs), of mouse somatic cell nuclear
transfer (SCNT) embryos for 24 h from 48 h (4-cell stage), 24 h (2-cell stage) or
immediately after oocyte activation on blastocyst formation rates and qualities of the
resultant blastocysts. Blastocyst formation rates (33.4–37.0%) were not improved by VPA
treatments compared with the untreated control (35.1–36.4%). However, immunofluorescence
staining revealed that Oct4 expression levels, evaluated from percentages of embryos
expressing Oct4 strongly and having more than 10 Oct4-positive cells, in blastocysts from
SCNT embryos treated with 1 mM VPA for 24 h from the 4-cell stage (VPA-4C) were highest
among all the groups and that the proportion of cells with a normal nuclear distribution
of histone H3 trimethylated at lysine 27 (H3K27me3), a marker of the state of X-chromosome
inactivation, significantly increased in the VPA-4C group (36.6%) compared with the
control group (12.4%, P<0.05). Treatments with scriptaid and sodium butyrate,
inhibitors of class I and IIa/b HDACs, for 24 h from the 4-cell stage also had beneficial
effects on SCNT blastocysts. These findings indicate that treatment with 1 mM VPA from the
4-cell stage improves the Oct4 expression and nuclear distribution of H3K27me3 in mouse
SCNT blastocysts and suggest that the inhibition of class I and IIa HDACs from the 4-cell
stage plays an important role in these effects.
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Affiliation(s)
- Yuuki Isaji
- Laboratory of Reproductive Biology, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan
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Bermejo-Alvarez P, Ramos-Ibeas P, Gutierrez-Adan A. Solving the "X" in embryos and stem cells. Stem Cells Dev 2012; 21:1215-24. [PMID: 22309156 DOI: 10.1089/scd.2011.0685] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
X-chromosome inactivation (XCI) is a complex epigenetic process that ensures that most X-linked genes are expressed equally for both sexes. Female eutherian mammals inactivate randomly the maternal or paternal inherited X-chromosome early in embryogenesis, whereas the extra-embryonic tissues experience an imprinting XCI that results in the inactivation of the paternal X-chromosome in mice. Although the phenomenon was initially described 40 years ago, many aspects remain obscure. In the last 2 years, some trademark publications have shed new light on the ongoing debate regarding the timing and mechanism of imprinted or random XCI. It has been observed that XCI is not accomplished at the blastocyst stage in bovines, rabbits, and humans, contrasting with the situation reported in mice, the standard model. All the species present 2 active X-chromosomes (Xa) in the early epiblast of the blastocyst, the cellular source for embryonic stem cells (ESCs). In this perspective, it would make sense to expect an absence of XCI in undifferentiated ESCs, but human ESCs are highly heterogeneous for this parameter and the presence of 2 Xa has been proposed as a true hallmark of ground-state pluripotency and a quality marker for female ESCs. Similarly, XCI reversal in female induced pluripotent stem cells is a key reprogramming event on the path to achieve the naïve pluripotency, and key pluripotency regulators can interact directly or indirectly with Xist. Finally, the presence of 2 Xa may lead to a sex-specific transcriptional regulation resulting in sexual dimorphism in reprogramming and differentiation.
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Theunissen TW, Silva JCR. Switching on pluripotency: a perspective on the biological requirement of Nanog. Philos Trans R Soc Lond B Biol Sci 2011; 366:2222-9. [PMID: 21727127 DOI: 10.1098/rstb.2011.0003] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Pluripotency is a transient cellular state during early development which can be recreated in vitro by direct reprogramming. The molecular mechanisms driving entry into and exit from the pluripotent state are the subject of intense research interest. Here, we review the role of the homeodomain-containing transcription factor Nanog in mammalian embryology and induced pluripotency. Nanog was originally thought to be confined to the maintenance of pluripotency, but recent insights from genetic studies uncovered a new biological function. Embryonic stem cells deficient in Nanog alleles are more prone to differentiate but do not lose pluripotency per se. Instead, Nanog is transiently required for the specification of the naive pluripotent epiblast and development of primordial germ cells. Nanog is also essential to finalize somatic cell reprogramming during induction of pluripotency. We propose that this unique transcription factor acts as a molecular switch to turn on the naive pluripotent programme in mammalian cells. In this context, the capacity of Nanog to resist differentiation can be regarded as recapitulation of effects normally associated with the specification of pluripotency. Pertinent questions are how Nanog specifies naive pluripotency and whether this mechanism is evolutionarily conserved.
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Affiliation(s)
- Thorold W Theunissen
- Wellcome Trust Centre for Stem Cell Research and Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QR, UK
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19
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Teichroeb JH, Betts DH, Vaziri H. Suppression of the imprinted gene NNAT and X-chromosome gene activation in isogenic human iPS cells. PLoS One 2011; 6:e23436. [PMID: 22022350 PMCID: PMC3192059 DOI: 10.1371/journal.pone.0023436] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2010] [Accepted: 07/18/2011] [Indexed: 01/21/2023] Open
Abstract
Genetic comparison between human embryonic stem cells and induced pluripotent stem cells has been hampered by genetic variation. To solve this problem, we have developed an isogenic system that allows direct comparison of induced pluripotent stem cells (hiPSCs) to their genetically matched human embryonic stem cells (hESCs). We show that hiPSCs have a highly similar transcriptome to hESCs. Global transcriptional profiling identified 102–154 genes (>2 fold) that showed a difference between isogenic hiPSCs and hESCs. A stringent analysis identified NNAT as a key imprinted gene that was dysregulated in hiPSCs. Furthermore, a disproportionate number of X-chromosome localized genes were over-expressed in female hiPSCs. Our results indicate that despite a remarkably close transcriptome to hESCs, isogenic hiPSCs have alterations in imprinting and regulation of X-chromosome genes.
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Affiliation(s)
- Jonathan H. Teichroeb
- Ontario Cancer Institute, Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
- Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada
| | - Dean H. Betts
- Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada
| | - Homayoun Vaziri
- Ontario Cancer Institute, Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
- * E-mail:
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Orkin SH, Hochedlinger K. Chromatin connections to pluripotency and cellular reprogramming. Cell 2011; 145:835-50. [PMID: 21663790 DOI: 10.1016/j.cell.2011.05.019] [Citation(s) in RCA: 303] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2011] [Indexed: 12/15/2022]
Abstract
The pluripotent state of embryonic stem cells (ESCs) provides a unique perspective on regulatory programs that govern self-renewal and differentiation and somatic cell reprogramming. Here, we review the highly connected protein and transcriptional networks that maintain pluripotency and how they are intertwined with factors that affect chromatin structure and function. The complex interrelationships between pluripotency and chromatin factors are illustrated by X chromosome inactivation, regulatory control by noncoding RNAs, and environmental influences on cell states. Manipulation of cell state through the process of transdifferentiation suggests that environmental cues may direct transcriptional programs as cells enter a transiently "plastic" state during reprogramming.
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Affiliation(s)
- Stuart H Orkin
- Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02115, USA.
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21
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Fan G, Tran J. X chromosome inactivation in human and mouse pluripotent stem cells. Hum Genet 2011; 130:217-22. [PMID: 21678064 DOI: 10.1007/s00439-011-1038-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2011] [Accepted: 06/07/2011] [Indexed: 10/18/2022]
Abstract
Since the groundbreaking hypothesis of X chromosome inactivation (XCI) proposed by Mary Lyon over 50 years ago, a great amount of knowledge has been gained regarding this essential dosage compensation mechanism in female cells. For the mammalian system, most of the mechanistic studies of XCI have so far been investigated in the mouse model system, but recently, a number of interesting XCI studies have been extended to human pluripotent stem cells, including both embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs). Emerging data indicate that XCI in hESCs and hiPSCs is much more complicated than that of their mouse counterparts. XCI in human pluripotent stem cells is not as stable and is subject to environmental influences and epigenetic regulation in vitro. This mini-review highlights the key differences in XCI between mouse and human stem cells with a greater emphasis placed on the understanding of the epigenetic regulation of XCI in human stem cells.
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Affiliation(s)
- Guoping Fan
- Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, 695 Charles Young Drive South, Los Angeles, CA 90095, USA.
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22
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XCI in preimplantation mouse and human embryos: first there is remodelling…. Hum Genet 2011; 130:203-15. [PMID: 21647603 PMCID: PMC3132436 DOI: 10.1007/s00439-011-1014-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2011] [Accepted: 05/19/2011] [Indexed: 12/21/2022]
Abstract
Female eutherians silence one of their X chromosomes to accomplish an equal dose of X-linked gene expression compared with males. The mouse is the most widely used animal model in XCI research and has proven to be of great significance for understanding the complex mechanism of X-linked dosage compensation. Although the basic principles of XCI are similar in mouse and humans, differences exist in the timing of XCI initiation, the genetic elements involved in XCI regulation and the form of XCI in specific tissues. Therefore, the mouse has its limitations as a model to understand early human XCI and analysis of human tissues is required. In this review, we describe these differences with respect to initiation of XCI in human and mouse preimplantation embryos, the extra-embryonic tissues and the in vitro model of the epiblast: the embryonic stem cells.
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Navarro P, Moffat M, Mullin NP, Chambers I. The X-inactivation trans-activator Rnf12 is negatively regulated by pluripotency factors in embryonic stem cells. Hum Genet 2011; 130:255-64. [PMID: 21544581 PMCID: PMC3132432 DOI: 10.1007/s00439-011-0998-5] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Accepted: 04/21/2011] [Indexed: 12/21/2022]
Abstract
X-inactivation, the molecular mechanism enabling dosage compensation in mammals, is tightly controlled during mouse early embryogenesis. In the morula, X-inactivation is imprinted with exclusive silencing of the paternally inherited X-chromosome. In contrast, in the post-implantation epiblast, X-inactivation affects randomly either the paternal or the maternal X-chromosome. The transition from imprinted to random X-inactivation takes place in the inner cell mass (ICM) of the blastocyst from which embryonic stem (ES) cells are derived. The trigger of X-inactivation, Xist, is specifically downregulated in the pluripotent cells of the ICM, thereby ensuring the reactivation of the inactive paternal X-chromosome and the transient presence of two active X-chromosomes. Moreover, Tsix, a critical cis-repressor of Xist, is upregulated in the ICM and in ES cells where it imposes a particular chromatin state at the Xist promoter that ensures the establishment of random X-inactivation upon differentiation. Recently, we have shown that key transcription factors supporting pluripotency directly repress Xist and activate Tsix and thus couple Xist/Tsix control to pluripotency. In this manuscript, we report that Rnf12, a third X-linked gene critical for the regulation of X-inactivation, is under the control of Nanog, Oct4 and Sox2, the three factors lying at the heart of the pluripotency network. We conclude that in mouse ES cells the pluripotency-associated machinery exerts an exhaustive control of X-inactivation by taking over the regulation of all three major regulators of X-inactivation: Xist, Tsix, and Rnf12.
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Affiliation(s)
- Pablo Navarro
- MRC Centre for Regenerative Medicine, Institute for Stem Cell Research, School of Biological Sciences, University of Edinburgh, King's Buildings, West Mains Road, Edinburgh EH9 3JQ, Scotland, UK.
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Makhlouf M, Rougeulle C. Linking X chromosome inactivation to pluripotency: Necessity or fate? Trends Mol Med 2011; 17:329-36. [PMID: 21411371 DOI: 10.1016/j.molmed.2011.02.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2010] [Revised: 02/04/2011] [Accepted: 02/07/2011] [Indexed: 01/19/2023]
Abstract
Silencing one X chromosome is essential for the development of female mammals, but the regulation of this process appears to vary between species. In the mouse, which has thus far been the leading model system in the field, X chromosome inactivation (XCI) is tightly coupled to pluripotency and the underlying mechanisms have just begun to be deciphered. However, mechanistic aspects of XCI regulation in other species have yet to be thoroughly investigated. Here we review current knowledge of the developmental regulation of XCI in mice and humans and discuss the extent to which the intimate link between XCI and pluripotency extends beyond rodents.
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Affiliation(s)
- Mélanie Makhlouf
- UMR7216 Epigenetics and Cell Fate, CNRS/Université Paris Diderot, 35 rue Hélène Brion, 75013 Paris, France
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26
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DNA Methylation Assay for X-Chromosome Inactivation in Female Human iPS Cells. Stem Cell Rev Rep 2011; 7:969-75. [DOI: 10.1007/s12015-011-9238-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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27
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Affiliation(s)
- Céline Morey
- Département de Biologie du Développement, Unité de Génétique Moléculaire Murine, Institut Pasteur, CNRS, Paris, France
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28
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Molecular coupling of Tsix regulation and pluripotency. Nature 2011; 468:457-60. [PMID: 21085182 DOI: 10.1038/nature09496] [Citation(s) in RCA: 153] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2010] [Accepted: 09/06/2010] [Indexed: 12/24/2022]
Abstract
The reprogramming of X-chromosome inactivation during the acquisition of pluripotency in vivo and in vitro is accompanied by the repression of Xist, the trigger of X-inactivation, and the upregulation of its antisense counterpart Tsix. We have shown that key factors supporting pluripotency-Nanog, Oct4 and Sox2-bind within Xist intron 1 in undifferentiated embryonic stem cells (ESC) to repress Xist transcription. However, the relationship between transcription factors of the pluripotency network and Tsix regulation has remained unclear. Here we show that Tsix upregulation in embryonic stem cells depends on the recruitment of the pluripotent marker Rex1, and of the reprogramming-associated factors Klf4 and c-Myc, by the DXPas34 minisatellite associated with the Tsix promoter. Upon deletion of DXPas34, binding of the three factors is abrogated and the transcriptional machinery is no longer efficiently recruited to the Tsix promoter. Additional analyses including knockdown experiments further demonstrate that Rex1 is critically important for efficient transcription elongation of Tsix. Hence, distinct embryonic-stem-cell-specific complexes couple X-inactivation reprogramming and pluripotency, with Nanog, Oct4 and Sox2 repressing Xist to facilitate the reactivation of the inactive X, and Klf4, c-Myc and Rex1 activating Tsix to remodel Xist chromatin and ensure random X-inactivation upon differentiation. The holistic pattern of Xist/Tsix regulation by pluripotent factors that we have identified suggests a general direct governance of complex epigenetic processes by the machinery dedicated to pluripotency.
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29
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Epigenetic modifications on X chromosomes in marsupial and monotreme mammals and implications for evolution of dosage compensation. Proc Natl Acad Sci U S A 2010; 107:17657-62. [PMID: 20861449 DOI: 10.1073/pnas.0910322107] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
X chromosome dosage compensation in female eutherian mammals is regulated by the noncoding Xist RNA and is associated with the differential acquisition of active and repressive histone modifications, resulting in repression of most genes on one of the two X chromosome homologs. Marsupial mammals exhibit dosage compensation; however, they lack Xist, and the mechanisms conferring epigenetic control of X chromosome dosage compensation remain elusive. Oviparous mammals, the monotremes, have multiple X chromosomes, and it is not clear whether they undergo dosage compensation and whether there is epigenetic dimorphism between homologous pairs in female monotremes. Here, using antibodies against DNA methylation, eight different histone modifications, and HP1, we conduct immunofluorescence on somatic cells of the female Australian marsupial possum Trichosurus vulpecula, the female platypus Ornithorhynchus anatinus, and control mouse cells. The two marsupial X's were different for all epigenetic features tested. In particular, unlike in the mouse, both repressive modifications, H3K9me3 and H4K20Me3, are enriched on one of the X chromosomes, and this is associated with the presence of HP1 and hypomethylation of DNA. Using sequential labeling, we determine that this DNA hypomethylated X correlates with histone marks of inactivity. These results suggest that female marsupials use a repressive histone-mediated inactivation mechanism and that this may represent an ancestral dosage compensation process that differs from eutherians that require Xist transcription and DNA methylation. In comparison to the marsupial, the monotreme exhibited no epigenetic differences between homologous X chromosomes, suggesting the absence of a dosage compensation process comparable to that in therians.
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30
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Dvash T, Lavon N, Fan G. Variations of X chromosome inactivation occur in early passages of female human embryonic stem cells. PLoS One 2010; 5:e11330. [PMID: 20593031 PMCID: PMC2892515 DOI: 10.1371/journal.pone.0011330] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2010] [Accepted: 05/27/2010] [Indexed: 12/22/2022] Open
Abstract
X chromosome inactivation (XCI) is a dosage compensation mechanism essential for embryonic development and cell physiology. Human embryonic stem cells (hESCs) derived from inner cell mass (ICM) of blastocyst stage embryos have been used as a model system to understand XCI initiation and maintenance. Previous studies of undifferentiated female hESCs at intermediate passages have shown three possible states of XCI; 1) cells in a pre-XCI state, 2) cells that already exhibit XCI, or 3) cells that never undergo XCI even upon differentiation. In this study, XCI status was assayed in ten female hESC lines between passage 5 and 15 to determine whether XCI variations occur in early passages of hESCs. Our results show that three different states of XCI already exist in the early passages of hESC. In addition, we observe one cell line with skewed XCI and preferential expression of X-linked genes from the paternal allele, while another cell line exhibits random XCI. Skewed XCI in undifferentiated hESCs may be due to clonal selection in culture instead of non-random XCI in ICM cells. We also found that XIST promoter methylation is correlated with silencing of XIST transcripts in early passages of hESCs, even in the pre-XCI state. In conclusion, XCI variations already take place in early passages of hESCs, which may be a consequence of in vitro culture selection during the derivation process. Nevertheless, we cannot rule out the possibility that XCI variations in hESCs may reflect heterogeneous XCI states in ICM cells that stochastically give rise to hESCs.
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Affiliation(s)
- Tamar Dvash
- Department of Human Genetics and The Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Neta Lavon
- The International Stem Cell Research Institute, Cedars Sinai Medical Center, Los Angeles, California, United States of America
| | - Guoping Fan
- Department of Human Genetics and The Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
- * E-mail:
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31
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Navarro P, Avner P. An embryonic story: Analysis of the gene regulative network controlling Xist expression in mouse embryonic stem cells. Bioessays 2010; 32:581-8. [DOI: 10.1002/bies.201000019] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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32
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Cox JL, Rizzino A. Induced pluripotent stem cells: what lies beyond the paradigm shift. Exp Biol Med (Maywood) 2010; 235:148-58. [PMID: 20404029 DOI: 10.1258/ebm.2009.009267] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The discovery that somatic cells can be reprogrammed to become induced pluripotent stem (iPS) cells has ushered in a new and exciting era in regenerative medicine. Since the seminal discovery of somatic cell reprogramming by Takahashi and Yamanaka in 2006, there has been remarkable progress in the characterization of iPS cells and the protocols used to generate them. The new information generated during the past year alone has vastly expanded our understanding of these cells. Accordingly, this review provides a basic overview of the different strategies used to generate iPS cells and focuses on recent developments in the field of iPS cells. In the final section, we discuss three broad, unanswered questions related to somatic cell reprogramming, which are just starting to be addressed.
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Affiliation(s)
- Jesse L Cox
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, 986805 Nebraska Medical Center, Omaha, NE 68198-6805, USA
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33
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Leeb M, Wutz A. Mechanistic concepts in X inactivation underlying dosage compensation in mammals. Heredity (Edinb) 2010; 105:64-70. [DOI: 10.1038/hdy.2009.181] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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Abstract
A fundamental goal in biology is to understand the molecular basis of cell identity. Pluripotent embryonic stem (ES) cell identity is governed by a set of transcription factors centred on the triumvirate of Oct4, Sox2 and Nanog. These proteins often bind to closely localised genomic sites. Recent studies have identified additional transcriptional modulators that bind to chromatin near sites occupied by Oct4, Sox2 and Nanog. This suggests that the combinatorial control of gene transcription might be fundamental to the ES cell state. Here we discuss how these observations advance our understanding of the transcription factor network that controls pluripotent identity and highlight unresolved issues that arise from these studies.
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Affiliation(s)
- Ian Chambers
- MRC Centre for Regenerative Medicine, Institute for Stem Cell Research, School of Biological Sciences, University of Edinburgh, King's Buildings, Edinburgh EH9 3JQ, UK.
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37
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Silva J, Nichols J, Theunissen TW, Guo G, van Oosten AL, Barrandon O, Wray J, Yamanaka S, Chambers I, Smith A. Nanog is the gateway to the pluripotent ground state. Cell 2009; 138:722-37. [PMID: 19703398 PMCID: PMC3437554 DOI: 10.1016/j.cell.2009.07.039] [Citation(s) in RCA: 760] [Impact Index Per Article: 50.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2009] [Revised: 06/10/2009] [Accepted: 07/23/2009] [Indexed: 01/04/2023]
Abstract
Pluripotency is generated naturally during mammalian development through formation of the epiblast, founder tissue of the embryo proper. Pluripotency can be recreated by somatic cell reprogramming. Here we present evidence that the homeodomain protein Nanog mediates acquisition of both embryonic and induced pluripotency. Production of pluripotent hybrids by cell fusion is promoted by and dependent on Nanog. In transcription factor-induced molecular reprogramming, Nanog is initially dispensable but becomes essential for dedifferentiated intermediates to transit to ground state pluripotency. In the embryo, Nanog specifically demarcates the nascent epiblast, coincident with the domain of X chromosome reprogramming. Without Nanog, pluripotency does not develop, and the inner cell mass is trapped in a pre-pluripotent, indeterminate state that is ultimately nonviable. These findings suggest that Nanog choreographs synthesis of the naive epiblast ground state in the embryo and that this function is recapitulated in the culmination of somatic cell reprogramming.
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Affiliation(s)
- Jose Silva
- Wellcome Trust Centre for Stem Cell Research, University of Cambridge, Tennis Court Road, Cambridge CB2 1QR, UK
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QR, UK
- Corresponding author
| | - Jennifer Nichols
- Wellcome Trust Centre for Stem Cell Research, University of Cambridge, Tennis Court Road, Cambridge CB2 1QR, UK
- Department of Physiology, Development, and Neuroscience, University of Cambridge, Tennis Court Road, Cambridge CB2 1QR, UK
| | - Thorold W. Theunissen
- Wellcome Trust Centre for Stem Cell Research, University of Cambridge, Tennis Court Road, Cambridge CB2 1QR, UK
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QR, UK
| | - Ge Guo
- Wellcome Trust Centre for Stem Cell Research, University of Cambridge, Tennis Court Road, Cambridge CB2 1QR, UK
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QR, UK
| | - Anouk L. van Oosten
- Wellcome Trust Centre for Stem Cell Research, University of Cambridge, Tennis Court Road, Cambridge CB2 1QR, UK
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QR, UK
| | - Ornella Barrandon
- Wellcome Trust Centre for Stem Cell Research, University of Cambridge, Tennis Court Road, Cambridge CB2 1QR, UK
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QR, UK
| | - Jason Wray
- Wellcome Trust Centre for Stem Cell Research, University of Cambridge, Tennis Court Road, Cambridge CB2 1QR, UK
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QR, UK
| | - Shinya Yamanaka
- Department of Stem Cell Biology, Institute for Frontier Medical Sciences, Kyoto University, Kyoto 606-8507, Japan
| | - Ian Chambers
- MRC Centre for Regenerative Medicine, Institute for Stem Cell Research, School of Biological Sciences, University of Edinburgh, King's Buildings, Edinburgh EH9 3JQ, UK
| | - Austin Smith
- Wellcome Trust Centre for Stem Cell Research, University of Cambridge, Tennis Court Road, Cambridge CB2 1QR, UK
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QR, UK
- Corresponding author
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